This could actually work 

Here is a VERY VERY rough 10 minute test I did tonight.
Excuse my 'test rig' - it is a small piece of perspex and some builders line and a very roughly cut heart shape 



This is it from the front - thats ONE piece of red cellophane - I will do it using 2 or 3 pieces to make it deeper/ richer colour when the proper time comes.
As I thought - this will be a SLOW and time consuming excercise to get all the reds in the right places - but maybe it will be worth it.